LONDON (Reuters) - Bayer AG and Onyx Pharmaceutical Inc.'s
key cancer drug Nexavar significantly raises the risk of high
blood pressure, U.S. researchers said on Tuesday.

Writing in the journal Lancet Oncology, the researchers
said people taking the drug generically known as sorafenib
should be closely monitored and treated for high blood pressure
to prevent cardiovascular complications.

Nexavar -- one of Bayer's top drug hopes -- is already
approved in Europe and the United States for kidney cancer, and
is Onyx's only drug on the market.

"Early detection and effective management of hypertension
might allow for safer use of this drug," Shenhong Wu of State
University of New York, Stoney Brook and colleagues wrote.
"Future studies will be needed to identify the mechanism and
appropriate treatment of sorafenib-induced hypertension."

ADVERTISEMENT

Representatives for the companies could not immediately be
reached for comment.

In November, the U.S. Food and Drug Administration (FDA)
approved Nexavar medicine to treat liver cancer in a move
extending drug's reach.

Trial results last June also showed the drug was the first
medicine to extend the life of patients with advanced liver
cancer in a large study -- adding about three months to
survival compared with a placebo.

Bayer has said it expects Nexavar to reach 1 billion euros
in annual sales if it gets approvals for treatment of various
cancer indications. In 2006 Nexavar sales hit 130 million
euros.

Wu and colleagues said the risk of hypertension with the
drug taken as a pill has so far been unclear because of the
limited number of patients in previous trials.

They conducted a review called a meta-analysis of nine
studies that included 4,599 patients and were published between
January 2006 and July 2007.

They found patients treated with sorafenib have a 23
percent higher chance of having an increase in blood pressure
than those not given the drug. The risk of developing a more
severe form of high-blood pressure rose 6 percent.

Liver cancer kills more than 600,000 people globally each
year and is currently treated with limited success using a mix
of surgery, radiation and chemotherapy.

Nexavar is also being tested against several other types of
cancer, including non-small cell lung cancer and breast cancer.